红地毯-2.2.2 没有内容

Question

Ruby: 2.0.0p0, Rails: 3.2.13,redcarpet: 2.2.2
application_helper.rb

def markdown(text)                                                                                                     
markdown_render = Redcarpet::Render::HTML.new(:hard_wrap => true, :no_styles => true)
markdown = Redcarpet::Markdown.new(markdown_render, :autolink => true, :no_intro_emphasis => true) 
markdown.render(text).to_html.html_safe   
end   

app/views/questions/new.html.erb

<%= simple_form_for @question do |f| %>
<%= f.input :title, :input_html => { :class => "span6" } %> 
<%= markdown(@question.content) %> 
<%= f.button :submit, :class => 'btn-primary' %> 
<%= link_to 'Cancel', @question.id.blank? ? questions_path : question_path(params[:question]), :class => "btn btn-danger" %>
<% end %>  

但是出现了错误:wrong argument type nil (expected String)，然后我把<%= markdown(@question.content) %>改成了<%= markdown(@question.content.to_s) %>，然后出现了这个错误:undefined methodto_html' for "":String，所以我把markdown.render(text).to_html.html_safe改成了markdown.render(text).html_safe在application_help.rb中，它只有标题输入字段，内容输入字段丢失了。
我该如何解决这个问题，如果你需要更多的信息，请告诉我。

Answer 1

试试下面的帮助器:

def markdown(text)
  if text.blank?
    nil
  else
    markdown = Redcarpet::Markdown.new(Redcarpet::Render::HTML, :autolink => true, :space_after_headers => true)
    markdown.render(text)
  end   
end  

Answer 2

这在Rails 4.1.0上对我有效。

将以下内容放入app/helpers/application_helper.rb:

def markdown(text)
if text.blank?
  nil
else
  markdown = Redcarpet::Markdown.new(Redcarpet::Render::HTML, :autolink => true, :space_after_headers => true, filter_html:     true, hard_wrap: true, link_attributes: { rel: 'nofollow', target: "_blank" }, space_after_headers: true, fenced_code_blocks: true, superscript: true, disable_indented_code_blocks: true)
  markdown.render(text).html_safe
  end   
end

认为唯一的区别是把.html_safe放在末尾